After six years of
"Supernatural," we thought we'd seen it all, but when Sam (
Jared Padalecki) and Dean (
Jensen Ackles) killed the Mother of All in last week's episode, we were
shocked. After all, if they kill the big bad in Episode 19, what is there to do in episodes 20, 21, and 22? Sit around and pat each other on the back?

Unfortunately for the brothers Winchester, three episodes of celebratory air guitar wasn't in the cards. In the final scene of last week's episode, we learned that the Mother of All was the least of their worries. The angel on their shoulders, Castiel (
Misha Collins), had teamed up with the King of Hell, Crowley (
Mark Sheppard), who they'd presumed dead.

Life's just not fair sometimes.

This week's episode, "The Man Who Would Be King," was written and directed by producer
Ben Edlund - it's his "Supernatural" directing debut, though he's been with the show since Season 2. We were having some trouble wrapping our head around Castiel-as-bad-guy, so we spoke to Ben to see if he could set the record straight on where Cas straddles that line between good and evil.

"The real driving catalyst, the reason why more bad has happened to good people on 'Supernatural' this year than any other year, does
not come directly through the Mother of All monsters," Edlund tells Zap2it. "She's badass, and she does bad things, but it's this partnership between the angel and the demon that has driven most of our conflicts. It's all because of Crowley and Castiel."

Who knew that our friendly neighborhood angel baby-in-a-trenchcoat was capable of such deceit and destruction?

Dean Winchester certainly didn't. This Friday's episode serves as a shocking wake up call to Dean, especially given the fact that he's finally back on track with his brother, as he learns the extent of Castiel's betrayal. The hits just keep on coming for Dean, and this time, it's likely worse than you think.

"He won't like it. Familial betrayal is his kryptonite, so to speak. It's his
thing. It's the thing he hates worse than any other thing, and he has brought Cas into the family, so the math there has a clear outcome. It's going to hurt him deeply even to discover what we understand to be the case right now, which is that Cas is capable of working with a demon. Even that is going to be so painful. It's going to be a hard week for that good-looking bastard."

We asked Edlund whether the writers hesitated to explore Castiel's dark side, given his tendency to lend humor to the show. "I had my hesitations," he admits, "because I like the fish-out-of-water, dumb jokes, and I like Cas. I like the thing on camera that Misha created that complemented this new strain of creature, this angel coming into our world and gave a body and character to it. That's a really great thing. But one of the rules of 'Supernatural' is loss, and losing things. You have to love something before you can feel its loss."

Well... that sounds ominous.

Tune into "Supernatural" this Friday night at 9 p.m. EST on The CW, and check back in with Zap2it later this week for more "Supernatural" dish from Edlund.

In the meantime, weigh in below in our comments section. Do you see Castiel as a viable villain? How do you think this will play out?